A southern sleeper shark, a deep-sea predator typically found in warmer waters, has been documented further south in Antarctica than ever before. The discovery, captured by a remote underwater camera in January 2025, challenges long-held assumptions about the limits of shark distribution and survival in extreme environments.
Unprecedented Footage Reveals Shark in Antarctic Waters
Researchers from the Minderoo–University of Western Australia (UWA) Deep-Sea Research Center deployed a baited camera in a trench off the South Shetland Islands at a depth of 490 meters. After reviewing 400 hours of footage, they spotted the shark casually swimming in a relatively warmer subsurface layer of water — around 2 degrees Celsius.
“It was very surprising, as we didn’t think sharks were in Antarctic waters at all, let alone such a huge iconic one like the southern sleeper shark,” said Alan Jamieson, founding director of the center. The animal, estimated to be between three and four meters long, was identifiable by its unique appearance.
Why This Matters: Ecosystems and Adaptation
The sighting is significant because it suggests Antarctic waters may not be as shark-free as previously believed. Southern sleeper sharks are known for their exceptionally long lifespans (250-300 years) and slow metabolisms, traits that allow them to survive in food-scarce deep-sea environments. The presence of this female (identified by the absence of claspers) so far south indicates that these sharks might be more resilient to cold temperatures than scientists thought.
This discovery also raises questions about the broader Antarctic ecosystem. If sleeper sharks can tolerate these conditions, what other species might be lurking in the deep, unexplored trenches?
The Future of Deep-Sea Research
Sleeper sharks live in a habitat that makes them difficult to study; sightings remain rare. The UWA Deep-Sea Research Center’s findings highlight the importance of remote deep-sea monitoring for uncovering hidden biodiversity.
“This changes what we know about shark distribution and their ability to tolerate extreme environments,” the researchers stated. The discovery underscores how little we still know about life in the world’s most remote and harsh environments.
The Southern Ocean might not be as shark-free as we once thought, meaning further research is needed to understand the extent of these predators’ presence and their impact on the Antarctic food web.
